The Seven Percent Solution

Problem Description Uniform Resource Identifiers (or URIs) are strings like http://icpc.baylor.edu/icpc/, mailto:[email protected], ftp://127.0.0.1/pub/linux, or even just readme.txt that are used to identify a resource, usually on the Internet or a local computer. Certain characters are reserved within URIs, and if a reserved character is part of an identifier then it must be percent-encoded by replacing it with a percent sign followed by two hexadecimal digits representing the ASCII code of the character. A table of seven reserved characters and their encodings is shown below. Your job is to write a program that can percent-encode a string of characters. Character  Encoding " " (space)  %20 "!" (exclamation point)  %21 "$" (dollar sign)  %24 "%" (percent sign)  %25 "(" (left parenthesis)  %28 ")" (right parenthesis)  %29 "*" (asterisk)  %2a

Input The input consists of one or more strings, each 1–79 characters long and on a line by itself, followed by a line containing only "#" that signals the end of the input. The character "#" is used only as an end-of-input marker and will not appear anywhere else in the input. A string may contain spaces, but not at the beginning or end of the string, and there will never be two or more consecutive spaces.

Output For each input string, replace every occurrence of a reserved character in the table above by its percent-encoding, exactly as shown, and output the resulting string on a line by itself. Note that the percent-encoding for an asterisk is %2a (with a lowercase "a") rather than %2A (with an uppercase "A").

Sample Input Happy Joy Joy! http://icpc.baylor.edu/icpc/ plain_vanilla (**) ? the 7% solution #

Sample Output Happy%20Joy%20Joy%21 http://icpc.baylor.edu/icpc/ plain_vanilla %28%2a%2a%29 ? the%207%25%20solution

Source Mid-Central USA 2007

Recommend teddy

第一次直接用了cin输入，遇到空格就从新输入了，假如输入Happy Joy Joy! 相当于输了3个字符串，因此这里需要用到gets() 函数。

另外不知道为什么，刚开始头文件用<cstdio>  <string> 没有通过。代码附下：

#include <iostream>
#include <stdio.h>
#include <string.h>
using namespace std;
int main() {
	int i, len;
	char a[1000];
	while (gets(a)){
		len = strlen(a);
		if (len == 1 && a[0] == '#')
			break;
		for (i = 0; i < len; i++){
			if (a[i] == ' ')
				cout << "%20";
			else if (a[i] == '!'){
				cout << "%21";
			}
			else if (a[i] == '$'){
				cout << "%24";
			}
			else if (a[i] == '%'){
				cout << "%25";
			}
			else if (a[i] == '('){
				cout << "%28";
			}
			else if (a[i] == ')'){
				cout << "%29";
			}
			else if (a[i] == '*'){
				cout << "%2a";
			}
			else{
				cout << a[i];
			}			
		}
		cout << endl;
	}
	
	return 0;
}